php oop programming: building a class - php

Question

i am looking at building my first real class, i've played around with bits and bobs but its time to try it for real :)
what i am trying to do is have a form class which handles all my form submissions, checks the data entered and returns with either an error message or success message.
so here one of my forms, (i have 5 of these on 1 page)
<form action="include/mform.php" method="post" name="business_listing">
<input name="biz_name" type="text" value="Business or Place Name" />
<select name="biz_department">
<option value="">Business Sector</option>
<?php
$query = $user->database->query("SELECT * FROM tbl_sectors");
while($row=$user->database->fetchArray($query))
{
$id = $row['sectorID'];
$dept = $row['sectorName'];
echo "<option value='$id'>$dept</option>";
}?>
</select>
<input name="biz_address1" type="text" value="Street Name" />
<select name="job_location">
<option value="">Location</option>
<?php
$query = $user->database->query("SELECT * FROM tbl_places");
while($row=$user->database->fetchArray($query))
{
$id = $row['placeID'];
$dept = $row['placeName'];
echo "<option value='$id'>$dept</option>";
}?>
</select>
<input name="biz_phone" type="text" value="Contact Number" />
<input name="businessSubmit" type="submit" value="Submit" />
</form>
</div>
each of the form's action is set to include/mform.php which contains my class. within the class one of the first things it does is check to see which form was submitted and the idea is then to check the data that has been submitted and do whats necessary with it
my problem is that once my class knows which form was submitted what would be the best way to check the submitted data? should i create varibles within the function to get all the post data and take it from there or should i pass those in the actual function as parameters? , or does it matter?
here is my current class file which is a little bare atm
class Mform
{
private $values = array(); //Holds submitted form field values
private $errors = array(); //Holds submitted form error messages
private $num_errors; //The number of errors in submitted form
public function __construct()
{
if(isset($_POST['businessSubmit']))
{
$this->chkBusiness();
}
if(isset($_POST['jobSubmit']))
{
$this->chkJob();
}
if(isset($_POST['accommodationSubmit']))
{
$this->chkAccommodation();
}
if(isset($_POST['tradeSubmit']))
{
$this->chkTrade();
}
if(isset($_POST['eventSubmit']))
{
$this->chkEvent();
}
}
public function chkBusiness()
{
$field = "business";
}
public function chkJob()
{
return "job";
}
public function chkAccommodation()
{
return "accommodation";
}
public function chkTrade()
{
return "trade";
}
public function chkEvent()
{
return "event";
}
/**
* setValue - Records the value typed into the given
* form field by the user.
*/
public function setValue($field, $value)
{
$this->values[$field] = $value;
}
/**
* setError - Records new form error given the form
* field name and the error message attached to it.
*/
public function setError($field, $errmsg)
{
$this->errors[$field] = $errmsg;
$this->num_errors = count($this->errors);
}
/**
* value - Returns the value attached to the given
* field, if none exists, the empty string is returned.
*/
public function value($field)
{
if(array_key_exists($field,$this->values))
{
return htmlspecialchars(stripslashes($this->values[$field]));
}
else
{
return "";
}
}
/**
* error - Returns the error message attached to the
* given field, if none exists, the empty string is returned.
*/
public function error($field)
{
if(array_key_exists($field,$this->errors))
{
return "<font size=\"2\" color=\"#ff0000\">".$this->errors[$field]."</font>";
}
else
{
return "";
}
}
/* getErrorArray - Returns the array of error messages */
public function getErrorArray()
{
return $this->errors;
}
}
/* Initialize mform */
$mform = new Mform();
most of the individual functions just have return "word" as placeholder so i dont forget to do that function at a later date.
this is what i was thinking of doing for each of the individual form functions
public function chkBusiness()
{
$field = "business";
$name = $_POST['biz_name'];// all need to be sanitized!!
$dept = $_POST['biz_dept'];
$address = $_POST['biz_address'];
$location = $_POST['biz_location'];
$phone = $_POST['biz_phone'];
//start checking the input
if(!$name || strlen($name = trim($name)) == 0)
{
$this->mform->setError($field, "* Name not entered");
}
...
...
}
any help would be appreciated
Luke

Answer 1

I generate a class for every table in my database; life is too short to actually write that functionality for every database table!
Each field has it's own object containing it's value, type, maxlength etc. and the fields are also added to an array so I can do really cool things with them.
Each of the table classes extend a much bigger class that allows me to insert, update, delete and display as tables and forms... I can override any functions that are non-standard although that is very rare.
The performance overhead is about 0.001ms for iterating through about 25000 good sized records.
As an example, my code to produce a datatable of document records looks like this:
//Create object
$objDocument = new cls__CMS_Document();
//Set the fields you want to display in the datatable
$objDocument->objID->Active(true);
$objDocument->objDocument_Name->Active(true);
$objDocument->objAuthorID->Active(true);
$objDocument->objVersion->Active(true);
$objDocument->objDate_Created->Active(true);
$objDocument->objDate_Last_Edited->Active(true);
//Include a hyperlink from the ID field
$objDocument->objID->HyperLink('/drilldown.php');
$objDocument->objID->Post(true);
//Pass a field through a formatting function
$objDocument->objAuthorID->OutputFunction('getAuthorFromID');
$result .= $objDocument->displayTable($sqlConditions);
unset ($objDocument);
The best bit: every step of the way, the auto-complete works:) So you type $objDocument-> and all the methods and properties pop up including all the field objects so you never misspell them.
If I get enough interest (votes), I'll make the whole thing available on the net.
That should be food for thought though when making your own.